Overview of the Catesby Aero Research Facility (CARF), a Tunnel-Based Aerodynamic Proving Ground

Hiroshi Shimoyama･Hiroki Nagano･Satoshi Yoshizawa･Wataru Kato･Keiichi Watanabe (SUBARU)

The Catesby Aero Research Facility (CARF) is a tunnel-based aerodynamic proving ground put into operation in 2019 with investment from SUBARU through its corporate venture capital, and its facility characteristics and measurement technologies are presented. A 2.7 km straight track converted from a former railway tunnel enables continuous coast-down testing to very low speeds, providing higher repeatability than outdoor testing. The facility is expected to bridge the gap between CFD, conventional wind tunnel testing, and on-road testing.

Dynamic Aerodynamic Forces Generated by Vehicle Motion and Their Effects on Vehicle Motion
-Full-Scale Vehicle Excitation Tests in a Wind Tunnel-

Kazuhiro Maeda･Mitsuru Sugimoto･Yasuhiro Endo･Akinao Yamamoto (Toyota Motor)

To investigate the effects of aerodynamic devices aimed at improving vehicle dynamic performance, we focused on dynamic aerodynamic forces generated by vehicle motion rather than relying solely on steady aerodynamic forces. Full-scale excitation tests were conducted in a wind tunnel using a vehicle. The results showed that the oncoming flow makes the front of the vehicle less responsive to excitation while making the rear more responsive. In addition, when the flow becomes disturbed, the vehicle tends to move less easily, whereas flow rectification increases its ease of motion. These findings confirm the influence of dynamic aerodynamic forces on vehicle motion.

Wind Tunnel Evaluation of Combined Active Aerodynamic Systems on a CUV-type EV

Dong Ha kim･Hak Lim kim･Hong Hee lee･Jin Young youn･Su Bok kim･Suk Bom son･Woo Jae Kwon･Ju Wan Han･Woo Yul Baek (Hyundai Motor)

This study investigates the combined aerodynamic effects of three active systems Active Air Skirt, Active Rear Diffuser, and Active Spoiler Module on a CUV-type EV through wind tunnel testing. Results confirm a total drag coefficient improvement of delta Cd 0.023 versus baseline, with negligible interaction between systems, enabling linear superposition for aerodynamic performance prediction. These findings serve as fundamental data for the development of effective combination and control strategies for EV active aerodynamic systems, ultimately contributing to improved energy efficiency in next-generation EVs.

Development of Truck Aerodynamic Technologies to Achieve Carbon Neutrality in the Logistics Sector

Yuta Hino･Yusuke Kitazawa･Takafumi Makihara (Toyota Motor)

The logistics sector is a key area for achieving carbon neutrality, and reducing the aerodynamic drag of trucks is an effective approach to improve fuel efficiency and cut CO₂ emissions. This study applied aerodynamic knowledge from passenger vehicles to a truck and evaluated drag reduction potential of each area using wind tunnel tests and CFD analysis. And based on truck-specific constraints, more practical aerodynamic measures were proposed. These measures demonstrated weight and cost-effective aerodynamic improvements for trucks, also achieving drag reduction without compromising other performance.

An Inverse Design Method Considering Design Constraints for Automotive Aerodynamic Development

Yusuke Yoshinaga･Takuya Yabu･Naoki Hamamoto･Yasuhiko Okutsu･Norimasa Hashimoto (Mitsubishi Motors)

In the contemporary automotive industry, there is an increasing demand to deliver high-quality vehicles to customers within a shorter development period. To shorten the development period, an inverse design approach based on a statistically constrained PCA space incorporating design knowledge is proposed. Under constraints that account for design freedom, shape candidates expected to improve aerodynamic performance are generated efficiently. By enabling direct exploration within feasible design regions, trial-and-error iterations are reduced, and more effective design exploration is facilitated. As a result, the design quality of early-stage aerodynamic performance is improved, contributing to a shorter development period.